Sound record



samuiin WHYTE. o. ,4 .7 a.

I f qmy lqy ngcolajPofiATION or NEW JERSEY N Drawing. Afibl catioagai dwas as; 1193 jgf PatenteddJrily, 2 33 a,

seem: R C R l The Present inv li l Tesla/5832110 l mina discsoundrecords;feach layer of wliich comf-j prises? a cellulose derivativeand a 3 plastifier; 'Itvjhas been proposed, in connectionv with 5 1'ecordSj 1CQ'nsisting ofthree layers, allicontam ng 'a cellulose ester,"to ;prov1def.--the in-1 'fternal layer with aQIaTg'eQrcontentpfplas'layers,

' 6011112411- and thus -iiealiv a l-word," the; 111-,

ticising material gthe'n the externalpm rs ternal layer of which has adifi'ei'ent; coeffi cient of I expansion to gthat of the external i "Inthelrecord the presentiinveiitionigall surfacel'layers contain fillin'g;material and the layers of. whichcompris'e a cellulose de' r i d rpl sfi al e erna 0 ina-n amount in=excess of anybontainedin the" internallayer andflin additionfhave a q 1 lower plastifier" content than thelatter, the

2.5- silica, black oxide ,ofiron or the like.

pressin'g with the softer core below'and'it 'is thus easier to obtainone-and-a-half times that'of cellulose derivawhile the content offilling material in this layer preferably should not constitutemoreinternal layer being thus made softerand ,more fiexible 'thantheexternalor surface layers. By fillingmaterial is meant any inertmaterialsuch as-barytes,-s late powder,

.The present invention provides a record of a limp nature which tendsftolie '-flat under allc'onditions, since the internal layer has nottheresilient qualitiesof theoutside of the presentinvention'isthat'pressing is;

for the'surface will flow more easily l-in a perfect: surface 'free efrom air marks.

The content of plastifierused in the "core or internal layer of a recordaccording to the invention may vary from one-half to tive present in thecore or internal"layer,-

than by weight of the total core mat rial. 1 6

Examples of compositidns preferred zfor the surface layers of; a recordaccording to the present invention are as :follows Black-oxideFiller"-..

. v Yter'al 'Illf] l' tl ltt t" 1 @5 layers; Aifurther advantage of therecord esp 601a y Wlen 16 c0n.ams

a --Th, -1" a di" t 1' a facilitated since the hard mater alnecessary eayers of a ream accor ng 0 he a solvent consisting of, for'example,

rial agi-1,927, and iii Great Britain February 5,

- Exam ples of compositions preferred (for the internal'layer are, astfollows,,the proper tlons n thisca'se also beinglby' weight; 1

Percent Percent 53 35 Cellulose acetate l l Plastifier Pi ment i presentinvention may be prepared by any suitablemethod. For example, in one orRE DHInIL'c Euetaiiiif Asmara: .To. mesa #TALKINGjllIAGHJlhTE] methodthecomponents are 'mixed together withtwo tothree timestheiritotahweightof acetone, 10% r nethyla'ted spirits and"l 5j%' on. a The film formedisthenstripped fromthe belt,i"seasoned and blanked out into discs ofsuitable size. I

: methyl ethyl ketone, to; form a paint which 1 is spread on to acanvasbeltand dried'the're In an alternative method, the components l areformed intoa plastic mass by malaxation with a volatile solvent, such asacetone, on heated rolls at atemperature preferably besqueezed betweenheavy rollers to form sheets (of the desired thickness These 1sheets-are seasoned and blanked out; into discs of suitable size.

The various layers are united under'heat i low the boiling point of thesolvent and then and pressure to'form record preferably I at the samemomentas thesound trace is inn-V parted thereto; Thepreferred form ofrecrd consists of atsofter layer hayinga herd layer attache el te. [eachside-thereof. :Infe a" flexible record of this type the core may be.010, thick; endfleaeh external layer ,005"

thiek, "the" cemplete receid being apprhXi-f mately .02 thick,

thereof are possible.

'prio'i" (lift by the spirit of the appended claims L: 1

pla'stifiercentent'than said innerfla'yeis, said other layeri beingsofter and I claim as my inventionifi 1; laminateddisesonndrefcordbmpiisI inge plurality (iflayers'of. a icellfilese derivative and apltstifi'er- Whereinthequantity fof plistifiel" present in theinternalla-yer isinot less than one' halfthet of the Cellulosederivative present'in seid leyeis;

2. A laminated disc sound reeoi d eomprising a luralit of layers o e-ce1hf11o;se"decontaining filling material in an, amount not" more than %;byWeight of the matei'iel forming said layer and "having greater than saidother layer.

3, A laminated disc sound record 'c'ompris-s rivative and a plastifierWhereinthequantity of. plastifier present in the internal layer does notexceed one and a'helf times that ;'of Cellulose deriyetive;.present insaidlayers, said internal'leyer'also containing-"a filling lnaterial" inan amount not more than 25% by Weight of thejmaterial forming saidlayer. l

I 4. laminated disesound record comprising a plurality ofleyers of acellulose derivetiyeend; eplestifier wherein the quantity 0i'iilastifier present in the internal layer is nielfinien amount "notmore than 25% by ln'g eplnrelity of layers fha cellulose 'det no lessthanqnehalfthat (if thelcellnlo'se d'eliyzdziveV present,ii ;saidlayers, said in teriiel leyerfllso containing a; fillingmate 1 weightofthe material forming said layer,

"15$ Ala'minated disc seundv yecord' compi'is-i ing ejplui'ality oflayersidfe eellulese derivetivej and e lalastifier wherein the quantity0f p'lestifiei' present in; the internal layer is V not less thanOne"l'ialf that of cellulose (1e; riva-tiveand a plastifier, theinternal; layer i'ivetive present nor in excess-0f one and one halftimes that of eelhilese deriyative presnee-mere thai1i25%' Weight of themate;

i'ialj femin'gsaid layer.

- SAMUEL We I

